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Corrosion Under Insulation (CUI) / Corrosion Protection
For iron to become iron oxide, three things are required: iron, water and oxygen.
Here's what happens when the three get together:
When a drop of water hits an iron object, two things begin to happen almost immediately. First, the water, a good electrolyte, combines with carbon dioxide in the air to form a weak carbonic acid, an even better electrolyte. As the acid is formed and the iron dissolved, some of the water will begin to break down into its component pieces -- hydrogen and oxygen. The free oxygen and dissolved iron bond into iron oxide, in the process freeing electrons. The electrons liberated from the anode portion of the iron flow to the cathode, which may be a piece of a metal less electrically reactive than iron, or another point on the piece of iron itself.
The corrosion-related cost to the transmission pipeline industry is approximately $5.4 to $8.6 billion annually. This can be divided into the cost of failures, capital, and operations and maintenance (O&M) at 10, 38, and 52 percent, respectively.
Corrosion Under Insulation is a multi-billion dollar problem that destroys expensive industrial infrastructure and causes continuous scheduled manufacturing plant and facility downtime to conduct inspections for failure and unexpected downtime when equipment failure occurs.
THE SOLUTION: The effectiveness of Nanotechnology coatings in preventing Corrosion Under Insulation (CUI) while providing excellent thermal insulation was difficult to create... but it is easy to explain.
First:
Hydrophobic refers to the tendency of a substance to repel water.
Due to the fact that these coatings adheres directly to the substrate being insulated, it coats the substrate with the hydrophobic particles which act to continuously repel any attempt at moisture build-up and no moisture means excellent rust prevention and corrosion protection.
Second:
Nanotechnology coatings adhere directly to the substrate, bonding with it. There is no... and we mean not even microscopic... space for air and the life giving oxygen that rust needs to grow.
Insulation
There is ALWAYS a heat source that is causing the customer's problem.
Pipes: A pipe with hot fluid in it is losing heat energy (the fluid cools) because the heat of the fluid (generated at some point by a heat source) is trying to "get out" to the cooler area around the pipe.
A pipe with cold fluid is gaining heat energy (the fluid warms) because the heat of the outside area (heat source is the sun or equipment in the area that generates heat, such as a furnace) is trying to "get in" to the cooler area in the pipe.
Buildings: In a building in summer, the heat outside the building (the source is the sun) is trying to move to the cooler area in the building.
In a building in winter, the heat inside the building (the source is the heaters) is trying to move to the cooler area outside the building.
The heat is summer is "coming in" through the walls and roof faster than the heat reducing element (the air conditioning) can reduce it.
The cold in winter is not "coming in". The heat inside the building is leaving through the walls and roof faster than the heat source (the heater) can replace it.
Everything in the world is trying to reach equilibrium, or balance. If you pour water into one end of a long trough, it will move to the other end until it is evenly distributed... until it has reach equilibrium.
An area of faster moving (warmer) molecules tries to "dissipate" some of the energy to the adjacent slower moving (cooler) molecules in order to reach equilibrium... where all the molecules are vibrating at the same rate of speed.
If you put a barrier (the wall of a metal pipe, or a piece of insulation) between the warm, faster vibrating area of molecules and the cooler, slower vibrating area of molecules, you reduce the rate at which this energy can be transferred and therefore the rate at which heat can move to cold.
...and that brings us to, INSULATION.
There are ways you can save energy without need for costly new equipment or complicated changes to your current operations. And every bit of energy saved means more money in your bottom line.
All Combustion Systems
- Operate furnaces and boilers at or close to design capacity
- Reduce excess air used for combustion
- Clean heat transfer surfaces
- Reduce radiation losses from openings
- Use proper furnace or boiler insulation to reduce wall heat losses
- Adequately insulate air or water-cooled surfaces exposed to the furnace environment and steam lines leaving the boiler
- Install air preheat or other heat recovery equipment
Steam Generation Systems
- Improve water treatment to minimize boiler blowdown
- Optimize deaerator vent rate
- Repair steam leaks
- Minimize vented steam
- Implement effective steam trap maintenance program
- Use high-pressure condensate to make low-pressure steam
- Utilize backpressure turbine instead of pressure-reducing or release valves
- Optimize condensate recovery
Process Heating Systems
- Minimize air leakage into the furnace by sealing openings
- Maintain proper, slightly positive furnace pressure
- Reduce weight of or eliminate material handling fixtures
- Modify the furnace system or use a separate heating system to recover furnace exhaust gas heat
- Recover part of the furnace exhaust heat for use in lower-temperature processes
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